1. Technology Field
The present invention generally relates to a data read method of a flash memory, and more particularly, to a data read method for reading data from a plurality of flash memory modules and a flash memory controller and a flash memory storage system using the same.
2. Description of Related Art
Flash memory is one of the most adaptable memories for battery-powered portable electronic products due to its data non-volatility, low power consumption, small volume, and non-mechanical structure. For example, a solid state drive (SSD) is a storage device that uses a NAND flash memory as its storage medium, and which has been broadly used in notebook computers as the main storage device.
Generally speaking, when a host system is about to read data stored in a flash memory storage device, a control circuit of the flash memory storage device reads the corresponding data from a flash memory chip of the flash memory storage device according to a host read command received from the host system through a flash memory interface. After that, the control circuit transfers the data to the host system through a connector of the flash memory storage device. Herein the process for reading the data from the flash memory chip is referred to as internal data transfer, and the process for transferring the data to the host system is referred to as external data transfer.
The data transfer rates of connectors have been greatly increased along with the development of data transfer techniques. For example, a serial advanced technology attachment (SATA) connector offers a data transfer rate up to 15 gigabits (Gb) per second or even 30 Gb per second. However, if the internal data transfer rate is lower than the data transfer data of the connector, the efficiency of the entire storage system cannot be effectively improved. Thereby, how to shorten the time for executing host read commands has become one of the major subjects in the industry.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the present invention. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention, or that any reference forms a part of the common general knowledge in the art.